Detect if LTE or NR is in use nearby

[Albert van Harten, What The Hack Aps]

Before I ask my question, I'd like to introduce myself.
My name is Albert van Harten, I am the owner of the Danish company What The Hack ApS. I am an ethical hacker, newly CEHv12 trained, but not yet certified.

One of my customers is a school, who has planned to ban the use of smart phones during school time.
Of course, it is easy to detect smart phones as long as they use the school's Wi-fi. Another thing, though, is when a phone owner uses LTE or NR.
Is there any method to detect whether there are devices that use either LTE or NR?

Albert van Harten

[digininja]

I don't have an answer but it might be worth talking to any local prisons as they might have the same problems.